西昆仑塔什库尔干铁矿带矿床类型、成因及成矿规律

在对西昆仑塔什库尔干地块地质演化、含矿岩系、锆石U-Pb同位素年代学和典型铁矿床进行研究的基础上，总结了区域含矿建造的特征、时代、矿床类型及成矿规律。结果表明:西昆仑塔什库尔干地块原“布伦阔勒群”实际上发育古元古代(2 100~2 500 Ma)、寒武纪早期(510~540 Ma)等两期沉积成矿事件，同时在中晚元古代(800~1 800 Ma)和海西期—印支期(200~410 Ma)分别发生过强烈的变质和变形作用，局部富矿的形成可能与后期热液的叠加改造作用有关。区域铁矿可划分为两类:一为条带状铁建造遭受后期热液叠加改造的沉积变质型铁矿床，如赞坎、莫喀尔和吉尔铁克沟铁矿床，其形成环境为早元古代活动陆缘的弱氧化—还原的浅海相沉积环境，成矿物质来源于海底热液对基性火山岩的淋滤及少量陆源物质的风化；二为早寒武世海相火山-喷流沉积型铁矿床，如喀来子、老并和叶里克铁矿床，其形成条件为半深海—浅海相、弱氧化—半氧化的断陷盆地环境，成矿成岩物质主要来源于海底热水沉积及陆源物质。根据区域成矿规律，推测卡拉本—喀来子—莫拉赫一带是寻找早寒武世与海底喷流成矿系统有关的铁-多金属矿的有利地区，吉尔铁克沟—赞坎北地区、莫喀尔及其以南地区是赞坎铁矿带的北延和南延，是寻找古元古代沉积变质型铁矿的有利地区。

Deposit Types,Origin and Metallogenetic Regularity of Taxkorgan Iron Ore Belt in West Kunlun

Based on the studies of the geological evolution, field investigation of the ore-bearing rock series, zircon U-Pb isotope chronology and typical iron ore deposits of Taxkorgan Block in West Kunlun, the characteristics and forming ages of regional ore-bearing formation, ore deposit type and metallogenic regularity were summarized. The results show that the previously defined “Bulunkuole Group” actually contains Paleoproterozoic (2 100-2 500 Ma) and Early Cambrian (510-540 Ma) sedimentary metallogenic events, which are suffered to the intensely metamorphism and deformation in both Middle-Late Proterozoic (800-1 800 Ma) and Hercynian-Indosinian (200-410 Ma). Moreover, the genesis of the local high-grade ores may be related to the later hydrothermal activities. The regional iron deposits can be divided into two types. The first one is the meta-sedimentary type iron deposit that is superimposed and transformed by the later hydrothermal fluids; taking Zankan, Mokaer and Jiertiekegou as examples, they form in weakly oxic to reducing marine sedimentary environment of Early Proterozoic active continental margin and the metallogenetic materials are derived from the leaching of basic volcanic rocks by seafloor hydrothermal fluids and a small amount of terrigenous sediments input. The second type is the Early Cambrian marine volcanic exhalative sedimentary iron deposit, such as Kalaizi, Laobing and Yeleke sulfate-iron deposit; their depositional environment should be bathyal-neritic facies weakly oxic to suboxic faulted basin; and the ore-forming materials come from the submarine hydrothermal sedimentary and terrigenous materials input. According to the regional metallogenic regularity, it is speculated that Kalaben-Kalaizi-Molahe belt is the favorable area for prospecting the iron-polymetallic deposits, which associate with the Early Cambrian marine exhalative metallogenic system. While, Jiertiekegou-Zankanbei area, Mokaer and its southern area, which are the northward and southward extensional zones of Zankan iron ore belt, are both the favorable areas for prospecting the meta-sedimentary type of Paleoproterozoic iron deposits.